The goal for this project is to provide translators to allow for interoperability between applications based on ODF (OpenDocument) 1.0 standards and Microsoft OpenXML based Office applications. As a part of this interoperability initiative, add-ins are being developed that can be installed on top of Microsoft Office Word (document processing), Excel (spreadsheet) and PowerPoint (presentation) applications (Office 2007 / 2003 / XP version) to allow for opening and saving OpenDocument format / ODF files (.odt, .ods and .odp) that adheres to ODF 1.0 specifications. We also provide command line translator utilities that allow doing batch conversions.
The converter is based on XSL transformations between two XML formats, along with some pre- and post-processing to manage the packaging (zip / unzip), schema incompatibility processings and the integration into Microsoft Office applications like Word, Excel and PowerPoint. We chose to use an Open Source development model that allows developers from all around the world to participate & contribute to the project.
Along with the Add-ins for Microsoft Word (v1.0 released), Excel (under development) and PowerPoint (under development), we also provide a command line translator that allows doing batch conversions. These translators can also be run on the server side for certain scenarios.

As most company standard builds are now including Microsoft office 2007 you will start seeing more .docx documents. This has been covered time and time again but still people still ask the question.
If you wish to open up a .docx document in OpenOffice you can do this two ways: